Developing exploration of critical minerals

Text: Paula Böhling

The Geological Survey of Finland develops operating methods and models to speed up the exploration of critical minerals and metals. There is a growing demand for effective methods.

Increasing self-sufficiency in terms of critical minerals is one of the focus points of the mineral strategy of the EU and Finland. The aim is to decrease dependency on imports from outside the EU and, therefore, ensure the availability of raw materials for high-technology industries.

– As more and more critical minerals and metals are needed, self-sufficiency offers a significant competitive edge for the European industry, says Pertti Sarala, research professor at GTK.

Metals defined to be critical by the EU include rare earth elements (REE), antimony, cobalt, magnesium, niobium and platinum group metals (PGM) that are used in the electronics industry, smart products, catalytic converters and batteries.

– Currently, Finland’s production of critical minerals and metals, such as chromium and phosphates, is significant, even on an EU level. In addition, Finland, like other Nordic countries, has a significant potential for new profitable deposits, Sarala says.

A survey conducted by GTK indicates, for example, that there are rare earth elements in weathered bedrock areas in central Lapland, platinum group elements (PGE) in layered intrusions and a REE potential in weathered granite. Lithium deposits are also known to have elevated REE concentrations. Graphite potential has also been surveyed.

– Finland’s geodata material offers a good starting point for exploration. We have thorough knowledge of our bedrock and soil. Our surveys are extensive on a historical scale and information is widely available.

Critical minerals. Source: The European Commission. GTK’s surveys in Vuotso in northern Lapland indicate elevated concentrations of critical minerals and rare earth elements.
Critical minerals. Source: The European Commission. GTK’s surveys in Vuotso in northern Lapland indicate elevated concentrations of critical minerals and rare earth elements.

An instant analysis conducted already in the field

GTK’s Indika project (Automated identification of indicator minerals in the exploration of critical minerals, 2016–2018) investigates the suitability of new automated field methodologies for the exploration of indicator minerals.

Indicator minerals are interesting in terms of research in that they accompany specific ore types and, therefore, indicate the existence of an ore deposit. Usually, there are more indicator minerals and in a larger area than actual ore minerals, which makes mineral exploration easier.

– Using modern field analysers, such as portable XRD and XRF devices, samples can already be analysed mineralogically and geochemically in the field. Combined with the support of advanced electron optical methods, minerals can be identified automatically in full or in part, Sarala says.

The Indika project has produced a new pre-processing and research procedure for indicator mineral samples which has been tested in practice and documented. It speeds up the work process and improves the cost-efficiency of exploration. Another aim is to improve digital data collection and management.

According to Sarala, the developed operating methods and models are ideal for the exploration of new deposits, but they can also be used to identify older and existing mining areas.

– The results of the project support the implementation of the circular economy in the mining industry. New technologies enable, for example, the cost-efficient evaluation of the ore potential of existing tailings basins or adjoining rock piles on site. Existing mining areas may provide companies with opportunities for new business.

As a result of the Indika project, mining operators will work and interact more closely together, which is expected to benefit, for example mineral exploration companies. Research partners in the Indika project are GTK, Oulu University and Lapland University of Applied Sciences. In addition, the project parties work together with a number of companies operating in the industry.

Jens Rönnqvist, a geologist at Scandinavian GeoPool believes that exploration methods will become more diverse in the near future.
Jens Rönnqvist, a geologist at Scandinavian GeoPool believes that exploration methods will become more diverse in the near future.

Using the research results to produce benefits

Ab Scandinavian GeoPool Ltd, a seller of mineral exploration services and equipment in Finland, Sweden and Norway, is one of the companies and partners that utilise the results of GTK’s research. Its customers range from major mining corporations to smaller exploration companies.

– Usually we are able, together with the customer to select the best exploration method on the basis of bedrock geology. What is challenging is that the properties of critical minerals are so different and they appear in highly differing geological environments. This means that varied expertise and methods are required in exploration, says Jens Rönnqvist, a geologist at Scandinavian GeoPool.

It is advantageous to consulting companies if their methods have been tested and proven in practice.

GeoPool specialises in hyperspectral mapping which gives indications of the location of ore deposits. The company, together with the Indika project, is planning to test its recently acquired field spectrometer which directly indicates the name and consistency of indicator minerals.

Rönnqvist believes that exploration methods will become more diverse in the near future, as the need for critical minerals is continuously increasing and mineral resources are deeper and deeper. It is no longer possible to start drilling without sufficient initial information.

– We also need to be able to develop continuously. The mineral exploration market offers huge potential, as long as we lead the way for development.